.header {
  width: 100%;
  height: 40px;
  background-color: rgba(51, 51, 51);
}
.w {
  width: 1226px;
  margin: 0 auto;
}
.left {
  float: left;
}
.right {
  float: right;
}
ul {
  padding: 0;
  margin: 0;
  list-style: none;
}
.header-container {
  position: relative;
  height: 40px;
}
.header-container .left-item {
  position: absolute;
  height: 40px;
}
.header-container .left-item ul {
  height: 40px;
}
.header-container .left-item ul li {
  float: left;
  padding: 0 5px;
  color: #b0b0b0;
  font-size: 12px;
  line-height: 40px;
}
.header-container .right-item ul li {
  float: right;
  padding: 0 7px;
  color: #b0b0b0;
  font-size: 12px;
  line-height: 40px;
}
.header-container .right-item ul li:nth-child(1):hover {
  background-color: pink;
}
.site-header {
  height: 100px;
}
.site-header .site-left {
  height: 100px;
}
.site-header .site-left ul {
  margin-left: 180px;
}
.site-header .site-left ul li {
  float: left;
  line-height: 100px;
  font-size: 16px;
  padding: 0 7px;
}
.site-header:before {
  content: '';
  float: left;
  background: url("https://s02.mifile.cn/assets/static/image/logo-mi2.png") no-repeat;
  background-size: 56px;
  background-position: center center;
  width: 100px;
  height: 100px;
}
.search-input {
  height: 100px;
  width: 300px;
  background-color: pink;
}
